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Finding the Fourth Proportional to 385.19, 577.87 and 128.69

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Solution

The fourth proportional to 385.19, 577.87 and 128.69 is: 193.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.19 : 577.87 = 128.69 : x
  2. Step 2: Convert to fraction form
    385.19/577.87 = 128.69/x
  3. Step 3: Cross multiply
    385.19x = 577.87 × 128.69
  4. Step 4: Simplify right side
    385.19x = 74,366.09
  5. Step 5: Solve for x
    x = 74,366.09/385.19
  6. Step 6: Final answer
    x = 193.06

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.